Interactive display for use on an automatic guided vehicle

ABSTRACT

An AGV for transporting material between at least two pickup and delivery stands. The AGV has a chassis for carrying objects. A computer processor is supported by the chassis for controlling and monitoring AGV operation. An interactive display is connected to the computer processor and mounted on the chassis for displaying status, current assignment and diagnostic information relating to AGV operation.

This is a continuation of co-pending application Ser. No. 07/313,213filed on Feb. 17, 1989 now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to automatic guided vehicles (AGVs) and,more particularly, to an AGV having an interactive display fordisplaying diagnostic information.

In the field of material handling, most commonly in a warehouseenvironment, many articles must be stored in inventory and, anindefinite time later, retrieved for use. The larger the warehousefacility, the greater the number of objects that can be stored.

Moreover, large warehouse facilities require a great amount ofgeographical space. Not only are modern warehouses spread over a greatamount of distance, but their height allows a many objects to be stackedfor storage one above the other. Each object location or bin can beidentified along three axes: X, Y and Z. Thus, a warehouse location forany specified particular object can be uniquely identified.

When the warehouse is large, it becomes burdensome to move material fromone part of it (e.g., the port of entry) to another part thereof (e.g.,a storage bin). Moreover, certain warehouses house large objects,weighing many pounds or even tons. The combination of large objects tobe stored in a warehouse and great distances between pickup and delivery(P & D) stands is ideal for assigning tasks to automatic guidedvehicles. As used herein, the term "assignment" indicates an address ofa P & D stand for a pickup operation or for a deliver operation.

It has been found that guided vehicles moving over a buried inductivecable can perform many of the functions that humans perform without therequirement of lighting, heating, ventilation and air conditioning thatwould normally be required for a pleasant human work environment.Moreover, AGVs can be relied upon to operate continuously 24 hours perday. This advantage of performance over human laborers results ingreater efficiency for warehouse facilities.

As AGVs become more sophisticated, they begin to acquire the attributesof intelligent robots. Monitoring the status of each AGV and diagnosingits various conditions, therefore, requires corresponding sophisticatedtechniques.

Heretofore, AGV indicators and displays have not been particularly userfriendly. Operating status of AGVs has been determined by indicatorlights, which are simply indications of whether a machine is functioningproperly. Diagnostics, when performed, have to be done off line, oftenby using an oscilloscope and other equipment.

In certain more advanced systems, a small seven-segment display has beenused to identify specific error or status conditions. For example, "E99" might refer to a predetermined error condition. Referring to alook-up table would indicate that the vehicle had lost its guide wire,for example. Needless to say, the step of looking up such informationrequires time and effort taken away from system operation.

DISCUSSION OF RELATED ART

Generally speaking, there are presetnly two major types of automatedguided vehicle system for warehouses:

a) a system featuring a buried wire in the floor of a warehouse, thatguides the vehicle through given paths of the warehouse; and

b) a vehicle traveling on a warehouse path that is kept on track byoptical (e.g., laser) reflective units positioned above ground along theguide path.

Both of the aforementioned systems have drawbacks that have been foundto make the guidance of the vehicles unreliable.

In most of these systems, problems arise at intersections, and wherevehicles are caused to make turns or slow down for other vehicles intheir path.

Another formidable problem occurs at loading docks and depositing bays,where decisons must be resolved concerning priority status of eachvehicle.

U.S. Pat. No. 4,168,760; issued: Sep. 25, 1979, depicts a wire guidancesystem that makes decisions at vehicular intersections based uponcomparison of destination addresses stored at the intersections, therebyreducing the need to store large quantities of data in computer memory.

In U.S. Pat. No. 4,727,492; issued: Feb. 23, 1988, a system is disclosedfor guiding a vehicle along a given route or pathway by storing data inthe vehicle indicative of the path to be followed. The system alsofeatures a fixed target detection system utilizing a scanning laser.

In U.S. Pat. No. 4,791,570, issued: Dec. 13, 1988, a wire guided vehiclesystem is shown which features a computer that polls the status of eachvehicle for the purpose of maintaining proper traffic flow.

In U.S. Pat. No. 4,790,402; issued: Dec. 13, 1988, a laser guidedvehicular system is illustrated wherein laser beam reflectors arepositioned along the guide path for routing the vehicle. Certain targetsare bar coded to keep track of the vehicle position. The system alsofeatures reflective microwave sensors for speed and distance control.

U.S Pat. No. 4,361,202; issued: Nov. 30, 1982, describes a systemutilizing a sonic or radar collision avoidance system and a wireguidance technique. Transponders buried in the roadway provide positionand speed information.

In the U.S. Pat. No 4,215,759, issued: Aug. 5, 1980, a vehicle guidepath system is featured wherein the vehicle is steered and guided byradio control stations along the pathway.

U.S Pat. No. 4,322,670; issued: Mar. 30, 1982, teaches a guide wirevehicle tracking system with superimposed signals for negotiatingcurves.

While all of the above-identified systems function reasonably well, nonehas been found to be completely reliable.

It would be advantageous to provide a system whereby specific statusinformation could be displayed in human readable form.

It would also be advantageous to provide a diagnostic system that isself contained so that no additonal references need be consulted.

It would also be advantageous to provide an audible signal so that anoperator out of view of a visible display could obtain an audibleindication of the system status.

It would also be advantageous for an AGV display to impart informationregarding current status (e.g., destination, last address, guidancefrequency, frequency being sought and traffic control).

It would be advantageous to provide an AGV with a self-containedmechanism to diagnose or monitor its operation.

It would also be advantageous to provide an AGV with a display adaptedfor displaying diagnostic information.

It would also be advantageous for such diagnostic information to bedisplayed interactively.

It would also be advantageous to provide an audible mechanism forindicating AGV conditions.

It would also be advantageous to provide a manual controller forinterrogating the AGV system.

SUMMARY OF THE INVENTION

The present invention uses a guided wire system that is very accurateand versatile. The system features separate traffic and loading control.An on-board computer performs guidance control in conjunction with ahost computer for greater versatility. An EPROM in the vehicle computercan be programmed with the particular floor plan of the warehouse. Theon-board computer of each vehicle can be interrogated to determine thestatus of any system, and provide for both manual and stand-aloneoperation.

In accordance with the present invention, there is provided an AGV fortransporting material between at least two pickup and delivery stands.The AGV has a chassis for carrying objects. A computer processor issupported by the chassis for controlling and monitoring AGV operation.An interactive display is connected to the computer processor andmounted on the chassis for displaying AGV status, current assignment anddiagnostic information relating to AGV operation. The display presentsreal time information when the system is operating and diagnosticinformation when the system is undergoing maintainence.

BRIEF DESCRIPTION OF THE DRAWINGS

A complete understanding of the present invention may be obtained byreference to the accompanying drawings, when taken in conjunction withthe detailed description thereof and in which:

FIG. 1 is a schematic diagram of a typical automatic guided vehicle(AGV) system;

FIG. 2 is a perspective view of the AGV of this invention;

FIG. 3 is an exploded view of the AGV illustrated in FIG. 2;

FIG. 4 is an exploded view of the load-lifting mechanism of the AGVshown in FIG. 3;

FIGS. 4a and 4b depict exploded views of the suspension system for theAGV illustrated in FIG. 2;

FIG. 5a is a plan view of a display and control panel disposed on theright side of the AGV shown in FIG. 2;

FIG. 5b is a plan view of a second control panel disposed on an oppositeside of the AGV depicted in FIG. 2;

FIGS. 6a-6d are plan views of the various sides of a hand-held controlwand that plugs into the control panel shown in FIG. 5a, which is usedto manually control and interrogate the AGV;

FIG. 7 is a schematic block diagram of the communication and control ofeach individual AGV of the system shown in FIG. 1;

FIGS. 8a-8d, when taken together and arranged as shown in thecorresponding interconnection diagram, and hereinafter identified asFIG. 8, are a schematic block diagram of the computer shown in FIG. 7;

FIG. 9 is a block diagram depicting the functionality of the LAC;

FIG. 10 is a block diagram depicting the functionality of the hyperdriver shown in FIG. 1;

FIG. 11 is a block diagram depicting the functionality of a control box(CB) as shown in FIG. 1;

FIG. 12 is a flow chart for one of the functions of the CB depicted inthe system of FIGURES;

FIG. 13 is a flow chart for another of the CB functions, specificallythe intersection traffic controller;

FIGS. 14a-14f, when taken together and arranged as shown in thecorresponding interconnection diagram, and hereinafter identified asFIG. 14, are a schematic diagram of a signal conditioning card asdepicted in FIG. 8;

FIGS. 15a-15d, when taken together and arranged as shown in thecorresponding interconnection diagram, and hereinafter identified asFIG. 15, are a block diagram of a guidance control card as depicted inFIG. 8;

FIGS. 16a-16d, when taken together and arranged as shown in thecorresponding interconnection diagram, and hereinafter identified asFIG. 16, are a block diagram of a digital card as depicted in FIG. 8;

FIGS. 17a-17b, when taken together and arranged as shown in thecorresponding interconnection diagram, and hereinafter identified asFIG. 17, are a block diagram of a non-volatile memory system inaccordance with the present invention; and

FIGS. 18a-18d, when taken together and arranged as shown in thecorresponding interconnection diagram, and hereinafter identified asFIG. 18, are a block diagram of the traffic manager in accordance withthe present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of clarity, like components will have the samenumerical designation throughout the FIGURES.

Referring now to FIG. 1, the system of the present invention and a hostcomputer are shown generally at reference numeral 110. A host computer112, such as a Tandem mainframe computer, is a customer interface to theautomatic guidance vehicle system (AGVS) 114 of the present invention.

A local area controller (LAC) 116 provides the interface to hostcomputer 112. LAC 116 is a computer such as that manufactured by the ASTCorporation based on a Model No. 80286 microprocessor provided by IntelCorporation.

Connected to LAC 116 is a hyper driver (HD) 117, which is programmed tocontrol and pass communications information among a plurality of controlboxes (CBs) 119. Up to eight CBs can be configured in one system. Inaddition, HD 117 is programmed for passing communications informationbetween LAC 116 and CBs 119.

Connected to hyper driver (HD) 117 is a plurality of CBs 119, each ofwhich is programmed to communicate with and control the movement of oneor more AGVs 132. Two CBs are shown in this FIGURE. Communicationincludes controlling AGV movement at intersections of the guide path andat P & D zone clusters. Traffic control for each CB occurs within apredetermined jurisdiction 150 of the guide path 122. In addition, CBs119 are programmed to control and maintain the status of a plurality ofswitch boxes (SBs) 123. HD 117 is also connected to LAC 116.

Connected to CB 119 are:

1) a plurality of SBs 123, each of which is used for controllingdiscrete devices, as in a P & D stand switch;

2) an inductive communication device 121, used for passing communicationinformation between CB 119 and any one of the AGVs 132; and

3) HD 117.

Each CB 119 controls its own discrete guide path 122 including any ofthe subsystems of the AGV system 114, such as P and D stand clusters120, SBs 123, intersections 128, homes 125, battery charge area 124,maintenance area 126 and AGVs 132, the totality being referred to as aCB jurisdiction 150. Only one jurisdiction 150 is depicted in theFIGURE.

Connected to SB 123 are up to two P & D stand switches, a warehouse baydoor, a light, or any other discrete device that can provide a two bitinput to SB 123 and be controlled by a single bit output.

An inductive communication device (ICD) 123 is connected to guide path122. Communication information is inductively passed through guide path122 to AGVs 132.

A guide wire communications network 122 is laid out in a facilitybeneath the surface of the warehouse floor, not shown. At variousstations along guide path 122 are areas 124 for recharging the batteriesof AGVs 132, areas for storing AGVs between assignments (home or parkingposition) 125 and areas for performing maintenance 126.

The AGVs of the present invention are programmed to travel to batterycharge area 124 when their battery voltage level is less than apredetermined amount and programmed to travel to maintenance area 126for predetermined preventive maintenance scheduling.

LAC 116 is an intelligent device that is loaded with a program forcontrolling it. The program is shown in Appendix I (not reproduced herebut available in application file).

Along guide wire 122 is an intersection 128 of guide wire paths. Itshould be understood that a plurality of intersections may occur in anygiven layout. Traffic control in an intersection 128 is provided by asoftware program within CB 119.

One or more AGVs 132 operate along guide wire 122 in a manner describedhereinbelow. Within AGV 132 is a vehicle control program shown inAppendix II (not reproduced here but available in application file).

Referring to FIG. 2, the automatic guidance vehicle (AGV) 132 of thisinvention is illustrated. The AGV comprises a rectangular housing 202containing internal guidance and control mechanisms, which are shown inFIGURE 3, and which will be explained in detail hereinafter.

On top 201 of housing 202 is disposed an expandable load-lifting table204, that is capable of depositing or removing items from P & D stands.

On right side 206 of housing 202 is a display and control panel 208 formanual control and interrogation of the vehicle as will be explained inmore detail, hereinafter.

On the front face 210 and rear face 211 of housing 202 are severalsensors 203, 205 and 207, respectively, for determining obstructions inthe travel path of vehicle. Sensors 203 are infrared light beamproximity sensors that detect a reflected beam from an object at adistance of six feet, and provide a signal to slow the vehicle to halfspeed.

Sensors 205 are similar to sensors 203 and cause the vehicle to come toa stop when an object is detected at a distance of three feet. Sensors203 and 205 can be purchased from Opcon, Model Nos. 1355A or 1356A.

A flexible bumper band 215 is disposed at the front and rear of thevehicle, respectively. The flexible bumpers 215 are semi-circular inshape, and are supported by guy-wires 216.

When an object contacts either bumper sufficient to distort itssemi-circular shape, sensors 207 detect the displacement and cut powerto the drive system. This is achieved by means of reflective spots 218that are disposed on the inside surface 219 and reflect the sensor beamfrom each bumper band 215 back to sensors 207. Sensors 207 can bepurchased from OPCON, Model 1456A.

The headlights 220 disposed on front and rear surfaces 210 and 211,respectively, act to light the path of travel and also act as warningflashers when an obstacle is detected.

An easily removable panel 213 located on side 206 of housing 202provides access to a battery pack that powers the vehicle 132 A similarpanel is disposed on the other side of the AGV.

Sensor 260 (Opcon Model No. 1356A) mounted on top 201 of housing 202(FRONT & REAR) sense when a cargo bay or stand is filled.

Sensors 230 (OPCON Models 1155A and 1255A) mounted at the base ofbumpers 215 on either side, provide power interrupt signals when anobject or foot brushes against right side 206 or its opposite side.

Sensors 250 (Opcon Model No. 1355A) mounted on the side 206 sense whenthe AGV has entered a cargo bay or stand.

Referring to FIG. 3, the AGV 132 is depicted in greater detail with thevarious component parts illustrated in exploded view. The AGV 132 isconstructed upon a main frame 300 about which all the parts are easilyaccessible.

Front and rear sides 210 and 211, respectively are fashioned as hingedcovers that articulate about hinges 310 and 311, respectively. Hinges310 and 311 are secured to main frame 300. These hinged covers provideeasy access to front and rear wheel assemblies 320 and 321,respectively. The front wheel 325 is a servo driven wheel, and movablypowers the vehicle. (Its matching rear wheel 326 is not powered, and itssteering mechanism is functionally and electrically independent withrespect to front wheel 325.) The wheel 326 is directionally controlledby sprocket gear 327, which turns the idler caster housing 328. Thefront drive wheel 325 is supported in a SUMITOMO housing, Model No.C0303S, manufactured by Big Joe Manufacturing Co., and is alsodirectionally controlled by a sprocket gear 327. Each sprocket gear 327is rotated by sprocket chain 329, which is driven by cog 330. The cog330 is powered by a servo motor 331.

The front wheel 325 is powered by drive motor 332. A tachometer 333attached to motor 332 measures the number of revolutions, and in thisway, the distance the vehicle travels is measured, since the diameter ofwheel 325 is known.

The AGV 132 has a balance wheel 340 (only one shown here) on each side.An electromechanical brake 341 attached to wheel 340 causes the vehicleto stop, when the power is cut off.

The AGV 132 is powered by an easily accessible battery pack 342, whichis accessible for maintenance purposes through side doors 213 on eitherside of the vehicle, as aforementioned.

The battery pack 342 is slidably removable from the vehicle by virtue ofa deck of rollers 343 upon which the battery pack 342 is supported.

The AGV 132 is internally controlled by a computer 350, which is locatedbehind the display and control panel 208. the computer 350, and itsoperation, will be described in more detail, hereinafter.

The computer 350 is housed in a slidable draw 351 which is easilyaccessed by virtue of slide rails 352, which allows the computer 350 tobe removed from or repaired within the vehicle housing 202.

The power supplied by the battery pack 342 is distributed to thecomputer 350 and various drive and steering motors through a powersupply module and isolation switches housed in slidable draw 360, havingslide rails 361 to provide ease of access, as shown.

Mounted on the top plate 201 of AGV 132 is a hydraulically actuated liftmechanism 370, for pick-up and delivery of items in the warehouse inaccordance with the system illustrated in FIG. 1.

The lift mechanism 370 comprises a lift table 371, which is caused to beraised or lowered (arrows 375) for contacting and removing items storedin cargo bays or cargo stands (not shown).

The lift mechanism 370 is shown in more detail in FIG. 4.

The lift mechanism 370 is actuated by a hydraulic cylinder and pistonarrangement 410 which receives hydraulic fluid to retract piston rod 411(arrow 405) through hydraulic line 412. The hydraulic fluid pump andreservoir 322 shown in FIG. 3 are disposed inside the vehicle housing202.

The key 413 of piston rod 411 is rotatively secured to the lips 414 ofthe roller mechanism 415. The rollers 416 of roller mechanism 415 arefree to rotate about shaft 417, and are caused to roll upwardly (arrow420) along inclined plane 421 attached to one half of the cross-bars430, when the piston rod 411 is retracted.

As the rollers 416 roll up the inclined plane 421, the cross-bars 430are caused to expand (arrows 440), thus causing the lift table 371 towhich it is secured, to rise (arrow 450).

When the lift table 371 is to be lowered, the procedure is reversed, andpiston rod 411 is hydraulically allowed to return to its expanded restposition. The hydraulic cylinder 409 is rotatively secured to the topplate 201 of the AGV 132 about key 408. Arms 460, 461 and 462 ofcross-bars 372 of table 371 are rotatively secured at end fingers 480,481 and 482, respectively.

The other end of bars 460 and 461 have rollers 490 and 491, that arecaused to roll within frame 495 when the cross-bar mechanism 430 isactuated. Cross bar 462 is rotatively secured to the frame 495 at end496.

Frame 495 is bolted to top 201 of the AGV 132 through bolt holes 497.

A reflective beam sensor (Opcon Model No. 1356A) 498 attached to table371 provides a signal when table 371 is unloaded by reflecting andreceiving a beam bounced off reflector 499 mounted at the opposite endof table 371. Absence of the reflected beam indicates a load has beenplaced on table 371.

The lift table 371 is just one of many mechanisms which can be supportedor carried by the AGV 132.

For example, the lift table 371 may be replaced or used in conjunctionwith a robot arm for grasping, removing or placing items on the AGV 132.

Referring to FIGS. 3, 4a and 4b, a unique suspension system of the AGV132 will be explained.

The AGV 132 is driven by rotatively powering [front wheel] 325. Thisarrangement, however, causes a problem, which is uniquely solved by thevehicle suspension system.

The problem as experienced by the vehicle, occurs when the front wheel325 runs over a lower level surface than is contacted by both sidewheels 340 and rear wheel 326.

In this position, the front wheel 325 will immediately lose tractionwith the floor, because the weight of the vehicle is centered towardsthe back. The AGV will, therefore, become uncontrollable in a drivablesense.

In order to keep the front wheel 325 in continuous driving contact withthe floor, the suspension system of the AGV provides an upward torqueupon side wheels 340 via unique suspension linkage 390, which by equaland opposite reaction provides a down force on front wheel 325.

Each side wheel 340, typically shown in greater detail in FIG. 4b, isalso provided with anti-sway capabilities by suspension 390, illustratedin greater detail in FIG. 4a.

Both side wheels 340 are each rotatively journalled to pivotable frame487 via side journal bearings 485 and 486 disposed in the pivotalmounting frame 487, as depicted in the exploded view of FIG. 4b.

Mounting frame 487 is pivotally secured to mainframe 300 by means ofbearings 481 which allow flanges 482 of frame 487 to pivot (arrows 400)with respect to main frame 300.

The pivotable frame 487 is pivotably biased toward the floor, and hence,the wheel 340 is also pivotably biased against the floor by a pair ofcoil springs 489.

The ball jointed rods 500 and 501, respectively secure each side wheelframe 487 to socket 505 of lever arms 503 and 504, respectively of thesuspension mechanism illustrated in FIG. 4a.

The ball jointed rods 500 and 501 are each height adjustable by means ofturnbuckles 506.

The lever arms 503 and 504 are torsionally coupled to each other, andhence, side wheels 340 are torsionally coupled to each other, by meansof the torsion rod 510, that rotatively anchors to frame 300 via flanges511 and connects to each lever arm 503 and 504 within socket holes 508and 509, respectively.

Torsionally coupling the wheels 340 in this manner creates an upwardforce on both wheels 340 when front drive wheel 325 moves over a lowersurface.

The torsional coupling also creates an equal and opposite force on theopposite side wheel 340 every time one of the side wheels rolls over abump or hole in the roadway. This equal and opposite force produces ananti-sway condition that reduces side roll effects.

Referring to FIG. 5a, the control and display panel 208 is shown ingreater detail. The control and display panel 208 mounted on the rightside of the vehicle features a switch E for changing the AGV 132 fromautomatic to manual control. A hand-held control wand or manualcontroller 600, which will be described in greater detail with referenceto FIGS. 6a through 6d, is plugged into socket F, when it is desired tocontrol the vehicle manually, or to alternately interrogate the vehicle,as will be described in more detail hereinafter.

A visual indication of the remaining operating time or power of thebattery pack 342 (FIG. 3) can be continuously obtained in eitherautomatic or manual modes by reference to electronic indicator gauge G.

Switch A is an interrupt switch for stopping the AGV by means of aninterrupt program in the internal computer 350.

The start switch B overrides the interrupt of switch A, and reactivatesthe vehicle.

Switch C is an ignition switch that supplies power to the AGV viabattery pack 342.

Switch D is an emergency switch that cuts off power to the vehicle motorand steering systems, but maintains power to the computer 350.

The display H provides a visual screen for interrogating the vehicle byvarious program menus, as will be explained hereinafter.

A control panel 208' is disposed on the left side of the AGV, oppositeside 206.

The panel 208' has switches A', B' and C', that perform the samefunction as switches A, B and C on panel 208.

The panel 208' is convenient to stop the vehicle if an operator is onthe opposite side of the vehicle.

Referring now to hand-held wand 600 that plugs into socket F of panel208 (FIG. 5a), it will be observed that FIGS. 6a through 6d depict thefour faces of a generally rectangular wand. While a preferred embodimentof the wand switches is herein disclosed, it is to be understood thatother switch configurations and corresponding functions can also beused, as is well known in the art of manual controllers.

FIG. 6c depicts an emergency switch BB that interrupts the power to thevehicle. It is a double-throw switch that must be pressed again torestart the AGV.

FIG. 6b depicts a spring loaded deadman switch AA, which must becontinuously pressed in order to actuate the other switches on the wand.

FIG. 6d illustrates switches G', H', I' and J' that manually control thespeed and direction of the vehicle.

Switch G' controls the vehicle by commanding a slow speed to the rear.Switch H' is for a fast rear control. Switch I' is a slow forwardcommand, and switch J' is for fast forward.

Referring to FIG. 6a, switch F' controls the raising of the lift table371 (FIG. 3).

Likewise, switch E' commands the lift table 371 of the vehicle todescend.

Switch D' the brake 341 (FIG. 3) of the vehicle.

Switch K' is for interrogating the AGV via display H (FIG. 5a).

Potentiometer C' is used to walk the user through the displayed menus.

AGV 132 is capable of operating in either of two modes: automatic andmanual. Switch E of the display and control panel 208 (FIG. 5a) is usedto toggle between automatic and manual mode. In automatic mode, the AGVperforms tasks it has been assigned providing an alphanumeric readout ofits assignments on its interactive display 208.

AGV 132 receives its assignment from either LAC 116 when the AGV system114 is configured as an LAC system; or by program menus availablethrough placing AGV 132 in manual mode and using the manual controller600 (FIG. 6) to access the menus, when the AGV system 114 is configuredas a stand alone system (SAS).

When AGVs 114 is configured as an SAS, HD 117 and host computer 112 canbe eliminated.

In manual mode the operator has control of AGV 132. The optionsavailable to the operator at this point are to drive AGV 132 manually orto enter the off-line diagnostic mode.

Within the drive mode of operation, AGV 132 can operate manually, bymeans of the manual controller; or semiautomatically, by means of theinductive wire in combination with the manual controller.

Within the diagnostic mode, menus are used in combination with themanual controller to monitor status of AGV 132. For purposes of thisdescription, certain sample menus are disclosed as examples hereinbelow,but other diagnostic menus can also be used, depending upon the specificAGV and facilities configuration, without departing from the scope ofthe present invention.

The main diagnostic menu is shown as Example 1.0.

EXAMPLE 1.0 Main Diagnostic Menu ##STR1##

When INSTRUCTIONS is selected from the main diagnostic menu by themanual controller, the sub-menu shown as Example 2.1 is displayed.

EXAMPLE 2.1 Instructions HOW TO USE DIAGNOSTICS

PUSH THE ENTER BUTTON ON THE OPERATOR INTERFACE (OIM) TO ACTIVATE THEMENU

PUSH LIFT AND LOWER TOGETHER TO EXIT THE MENU

USE STEERING POT TO DIAL A MENU

When DISPLAY DIGITAL INPUTS is selected from the main diagnostic menu bythe manual controller, the sub-menu shown as Example 2.2 is displayed.

EXAMPLE 2.2 Display Digital Inputs ##STR2##

When TEST ANALOG INPUTS is selected from the main diagnostic menu by themanual controller, the sub-menu shown as Example 2.3 is displayed.

EXAMPLE 2.3 Test Analog Inputs ##STR3##

When INTERACTIVE SYSTEM TEST is selected from the main diagnostic menuby the manual controller, the sub-menu shown as Example 2.4 isdisplayed.

EXAMPLE 2.4 Interactive System Test ##STR4##

When TEST/ADJUST VOLUME is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu display is shown asExample 2.4.1.

EXAMPLE 2.4.1 Test Adjust Volume ##STR5##

When TEST PITCH CONTROL is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.2.

EXAMPLE 2.4.2 Test Pitch Control ##STR6##

When PPI 1 PORT A TEST is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.3.

EXAMPLE 2.4.3 PPI 1 Port A Test ##STR7##

When PPI 1 PORT B TEST is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.4.

EXAMPLE 2.4.4 PPI 1 Port B Test ##STR8##

When PPI 2 PORT A TEST is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.5.

EXAMPLE 2.4.5 PPI 2 Port A Test ##STR9##

When PPI 2 PORT B Test is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.6.

EXAMPLE 2.4.6 PPI 2 Port B Test ##STR10##

When PPI 2 PORT C TEST is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.7.

EXAMPLE 2.4.7 PPI 2 Port C Test ##STR11##

When PPI 3 PORT C TEST is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.8.

EXAMPLE 2.4.8 PPI 3 Port C Test ##STR12##

When PPI 5 PORT B TEST is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.9.

EXAMPLE 2.4.9 PPI 5 Port B Test ##STR13##

When PPI 5 PORT C TEST is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu display is shown asExample 2.4.10.

EXAMPLE 2.4.10 PPI 5 Port C Test ##STR14##

When MONITOR TRAFFIC FREQ. is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.11.

EXAMPLE 2.4.11 MONITOR TRAFFIC FREQ. ##STR15##

When TEST WASPOT is selected from the INTERACTIVE SYSTEM TEST sub-menuby the manual controller, the next menu displayed is shown as Example2.4.12.

EXAMPLE 2.4.12 Test Waspot ##STR16##

When TEST WHEEL TACH. is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.13.

EXAMPLE 2.4.13 Test Wheel Tach. ##STR17##

When TEST GUIDANCE ASSY. is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.14.

EXAMPLE 2.4.14 Test Guidance Assy. ##STR18##

When CALCULATE TRUCK SPEED is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.15.

EXAMPLE 2.4.15 Calculate Truck Speed ##STR19##

When CALIBRATE TRUCK OPTICS is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.16.

EXAMPLE 2.4.16 Calibrate Truck Optics ##STR20##

When GRAPH WASPOT RESPONSE is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.17.

EXAMPLE 2.4.17 Graph Waspot Response ##STR21##

When MONITOR GUIDANCE FREQ. is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.18.

EXAMPLE 2.4.18 Monitor Guidance Freq. ##STR22##

When TEST TRAFFICE XMIT. is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu display is shown asExample 2.4.19.

EXAMPLE 2.4.19 Test Traffic Xmit. ##STR23##

When SNIFF FLOOR CONFIG. is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.20.

EXAMPLE 2.4.20 Sniff Floor Config. ##STR24##

When TEST LIFT/LOWER DECK is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu displayed is shown asExample 2.4.21.

EXAMPLE 2.4.21 Test Lift/Lower Deck ##STR25##

When TEST P&D STAND is selected from the INTERACTIVE SYSTEM TESTsub-menu by the manual controller, the next menu display is shown asExample 2.4.22.

EXAMPLE 2.4.22 Test P&D Stand ##STR26##

CHOICE 23--CHOICE 60 of the INTERACTIVE SYSTEM TEST sub-menu are notused in the present configuration, but can be replaced by appropriateroutines for testing or monitoring different functions.

Referring now to FIG. 7, there is shown a schematic block diagram of thecommunication and control of an AGV 132 (FIG. 1). At the heart of theAGV system is a computer 350 (FIG. 3) such as a Model PC/XT manufacturedby IBM Corp. Computer 350 is self-contained, having a central processingunit (CPU), not shown, as well as internal random access memory andlogic as is conventionally found in a commercial personal computer. Infact, the mother board, not shown, of computer 350 is a standard PC/XTcomputer mother board that can be provided by the aforementionedmanufacturer.

Connected to computer 350 are a power supply and associated switches 712for controlling power distribution to the various portions of thevehicle 132.

Also connected to computer 350 are guidance controllers 714a and 714bfor providing guidance to the front and rear wheels 325 and 326,respectively of AGV 132. Steering controls 716a and 716b are provided tocontrol servo motors, not shown, for the front and rear wheels,respectively.

Also connected to computer 350 by means of a bidirectional line 718 aredrivers for control and display panel and for manual controller, showngenerally at reference numeral 720. While control and display panel andmanual controller drivers 720 are separate devices, they are shown inthis FIGURE as one unit for simplicity. The interaction between displaypanel and manual controller 720 with one another and with computer 350is generally via the aforementioned menu system.

Safety apparatus, shown generally at reference numeral 722, controlssuch equipment as bumpers and optics. Certain threshold limits aremonitored and controlled by this block 722, as is an emergency power off(EPO) switch D (FIG. 5a) hereinabove described.

Lift table 371 (FIG. 4) is controlled by computer 350 by means of alift/lower controller 724 connected to computer 350 and adapted tooperate pursuant to instructions thereof.

Also connected to computer 350 is a drive controller 726, including adrive servo motor, not shown.

Operating instructions for computer 350 are loaded in a PROM 728, whichis replaceable in accordance with the present invention and which isdescribed in further detail hereinbelow.

Computer 350 is also connected by means of a bidirectional bus 730 to acommunications controller 732, including ICD 121 (FIG. 1), which isinductively coupled to a buried wire, not shown. Communicationcontroller 732 therefore provides the interface between AGV 132 andlocal area controller 116.

Peripheral equipment 734, such as printers, keyboards, floppy or harddisk drives, plotters and the like, can be connected to computer 350with minimal effort, thereby allowing computer 350 to function as aconventional PC/XT with peripheral devices.

Referring now also to FIG. 8, there is shown a schematic block diagramof the computer 350 (FIG. 7) in greater detail.

Each of the blocks shown in FIG. 8 resides on a separate printed circuitboard or separate sub-assembly in computer 350 in the preferredembodiment. A signal conditioning block 810 is connected to a guidancecontrol, so-called Butterworth block 812. Also connected to Butterworthblock 812 is a sensor array 814 for guidance. Connected to signalconditioning block 810 and Butterworth card 812 are servo interfaces815a (front) and 815b (rear). Connected to servo interface cards 815 aresteering servos for the front 816a and 816b of the vehicle. Alsoconnected to servo interfaces 815 are front wheel angle sensorpotentiometers (WASPOT) 818a and 818b, respectively.

Front and rear optics 820a and 820b are provided for safety.Specifically, as mentioned above, the vehicle is slowed when a neutralwhite object appears within six feet of one of the sensors and thevehicle stops when a neutral white object appears within three feet ofanother one of the sensors. Power to the front and rear optics 820a and820b is provided through servo interfaces 815a and 815b, respectively.

A traction amplifier (PMC) 822 is connected both to signal conditioningblock 810 and to front servo interface 815a. The output of tractionamplifier 822 is applied to front and rear contactors 824a and 824b,respectively, for controlling a motor 826 in a forward or rearwarddirection, respectively.

Connected to signal conditioning block 810 is an output opto rack whichoptoelectronically isolates signal conditioning block 810 from any oneof the following devices: parking brake, load at P & D, optic power,bumper power, precision stop optic right front power, precision stopoptic left front power, right rear, left rear, right front, left frontlights and the main contactor, none of which is shown on this FIGURE.

An input opto rack 830 is connected to signal conditioning block 810 andreceives input signals from the aforementioned devices (e.g., parkingbrake). The connection between input opto rack 830 and signalconditioning block 810 prevents mutually exclusive operations fromoccurring, such as lifting and lowering the lift table 371 (FIG. 4)simultaneously. Connected to input opto rack 830 is a lift/lowercontactor 832 which, in turn, is connected to a lift/lower motor 834.

Also connected to signal conditioning block 810 is a horn driver 836which is connected to a speaker 838. Horn and speaker 836, 838 arecapable of generating a signal that is infinitely variable with respectto amplitude and frequency. It should also be understood that a speechsynthesizer can replace the horn driver 836, if desired, in a mannerthat is well known in the art.

Connected to signal conditioning block 810 are front and rear traffictransmitter drivers 840a and 840b, respectively. Traffic transmitterdrivers 840a and 840b drive inductive coils 842a and 842b, respectively,which are focused and directed toward the ground loop, not shown. Threefrequencies are used as a signal between traffic transmitters 840 andsignal conditioning block 810.

Any one frequency or any of certain combinations of two or threefrequencies can be used to signal a specific condition. For example, ifthe first frequency ft₁, is present (binary 1), then the vehicle 132 isphysically located on the floor. If frequencies ft₂, and ft₃ are presentin certain combinations, the vehicle 132 is directed variously to turnleft, to turn right, to maintain a straight orientation or to enter anelevator going up or down, respectively. Thus, the presence offrequencies ft₁, ft₂ and ft₃ may signal an elevator operation, whereasfrequencies ft₁ and ft₃ alone signal a right turn operation.

An electronic inductive sensor and interface is shown at referencenumeral 844. The inductive sensor is a low powered device containingsensor electronics and an antenna. It contains an inductive power sourceused to activate an electronic label, not shown, usually disposedbeneath the floor of a warehouse. The electronic label, in turn, isincited by the sensor and interface to transmit a signal in responsethereto. The entire electronic label/sensor/interface system isavailable from Namco Controls Co. of Mentor, Ohio and marketed under thetrademark SENSORNET I. Connected to the electronic label system 844 is adigital card 846. The input to digital card 846 is an RS232 serialcommunications bus. Digital card 846 receives input from a variety ofsources and interrupts system operation in response thereto. Forexample, the deadman switch AA (FIG. 6) of manual controller 848(references numeral 600 in FIG. 6) is input to digital card 846, as istachometer reading 854 and safety optics 852, as shown in FIG. 8.Moreover, a watch dog monitor in signal conditioning block 810 and abumper bit signal from signal conditioning block 810 is also input todigital block 846, described in greater detail hereinbelow.

A nonvolatile RAM card 850 contains information necessary to restart thesystem in the event of loss of power. Card 850 also contains theoperational program for AGV 132 residing in PROM 728 (FIG. 7) and isalso used to convert or interrupt a number of switches that can beoperated by manual controller 848, such as fast forward, slow forward,fast reverse, slow reverse and horn.

Front and rear receiver coils 856a and 856b, respectively, receiveinductive signals from the receive loop in guide path 122 and aretransferred to a daughter board 858. Daughter board 858 generates threebits in response to the receiver signals from received coils 856a and856b. The bits correspond to the aforementioned frequency binary bitsft₁, ft₂ and ft₃.

Referring now to FIG. 9 there is shown a functionality diagram of localarea controller 116 (FIG. 1). Host computer 112 is connected to a hostinterface 910, which performs three functions:

a) processes status inquiries 910,

b) stores/retrieves assignments and reroutes 914, and

c) receives unsolicited system status reports 916 to be transferred, inturn, to host 112.

In providing unsolicited system status reports 916 to host interface910, the system determines the optimal AGV for a given assignment 918.In processing status inquiries 912, the status of AGVs 132, CBs 119, P &Ds 120 and hyper driver is maintained 920. When an optimal AGV 132 isselected for assignment 918, the identification of the AGV istransferred to HD interface 922 which, in turn, transfers theinformation to the hyper driver 117. Any status of devices or locationsis generated by the hyper driver 117 and transferred through HDinterface 922 to block 920.

Referring now to FIG. 10 there is shown a functionality diagram of hyperdriver 117. LAC 116 is connected to LAC interface 1010, which receivesinformation from a CB status control block 1012 and AGV lost/locationstatus block 1014, LAC/CB communications block 1016 and p & D statuscOntrol block 1022. LAC interface 1010 transfers such information to LAC116.

A control box interface 1020 is provided for communicating with CBstatus control block 1012, AGV lost/location status block 1014, LAC/CBcommunications block 1016 and P & D status control block 1022. Connectedto CB interface 1020 are one or more CBs 119.

Similarly, a second CB interface block 1024 receives

data from a CB_(x) to CB_(y) message manager 1018, the function of whichis to communicate between CBs. The CB_(x) to CB_(y) message center is incommunication with the AGV loss/location status drop block 1014. Thesecond CB interface 1024 also communicates with one or more CBs 119. Thefunctional channel from block 1010 through blocks 1014, 1018 and 1024allows an AGV 132 to cross from the jurisdiction 150 one CB 119 to thejurisdiction of another CB.

It can be seen that the function of the hyper driver 117 is to allowcommunications from LAC 116 through blocks 1010, 1012 and 1020 as wellas through blocks 1010, 1016 and 1020 to specific CBs, ultimatelyreaching predetermined AGVs. Likewise, the status of specific AGVs isreturned by means of their respective CBs through the first CB interface120 and eventually back to LAC 116. Likewise, the status of the P & Dstands is relayed to or from LAC 116 and to and from respective CBs 119.

Referring now to FIG. 11, there is shown a functionality diagram forcontrol box (CB) 119 (FIG. 1). Control box 119 controls all vehicles 132and locations in a given jurisdiction 150 (FIG. 1). Similarly, statusfrom all vehicles 132 and devices in a given jurisdiction 150 isreloaded up through appropriate functionality channels to hyper driver117. Specifically, functionality channels include hyper driverinterfaces 1 and 2, 1112 and 1110, respectively, bay to bay AGV movementcontrol 1114, zone and intersection control 1116, LAC/AGV communications1118, P & D node communication/control 1120, AGV status control 1122, P& D interface 1126 and AGV interface 1124. Conductive communications 121are connected to AGV interface 1124.

Referring now to FIG. 12, a flow chart of one of the functions of thecontrol box 11 (FIG. 1) is shown. The software loaded in CB 119 isadapted to provide a number of functions, one of which is trafficmanagement within P & D zone clusters.

When an AGV (vehicle A) approaches a cluster of P & D stands, step 1210,the vehicle reads the code tag buried underground and CB, not shown,determines whether another AGV (vehicle B) is already in the specifiedcluster, step 1212. If that is the case, CB determines whether vehicle Bis merely passing through the cluster on its way to another destination,step 1214.

If vehicle B is not merely passing through, LAC 116 determines whethervehicle B has already pulled in to a P & D stand, step 1216. If vehicleB is not in a P & D stand, vehicle A must wait, step 1218, until thatevent occurs. Once vehicle B pulls into a P & D stand, step 1216,vehicle A may enter the specified cluster, step 1220.

At any point in the process, when CB 119 determines that it is safe forvehicle A to enter the cluster, the vehicle is instructed to do so, step1220.

Once in the cluster, CB 119 determines whether vehicle A must perform apickup or delivery operation, step 1222. The pickup or delivery ensues,step 1224. At this point, vehicle A is free to request permission toleave the P & D stand, step 1212, and the flow of operations continuesin the same manner as hereinabove described.

Referring now to FIG. 13, there is shown a flow chart for anotherfunction of control box 119 (FIG. 1). CB 119 monitors an intersection,step 1310. If an AGV 132 is in the intersection, step 1312, a stopcommand is transmitted at all intersection entrances, step 1314. Thisstop command prevents any other AGV from entering the occupiedintersection.

CB 119 determines whether AGV 132 has exited the intersection, step1316. Once the AGV has left the intersection, CB determines whether morethan one other AGV is waiting to enter the intersection, step 1318.

If only one or no AGVs are waiting, all intersection code tags arecleared, step 1320, so that the next approaching AGV may enter theintersection without delay. If, however, more than one AGV is waiting toenter the intersection, step 1318, CB chooses a code tag at oneintersection to be released, step 1322, thereby permitting only one ofthe waiting AGVs to enter the intersection while prohibiting allremaining AGVs from doing so.

Monitoring the intersection, step 1310, continues indefinitely.

Referring now to FIG. 14, there is shown the signal conditioning card810 (FIG. 8) in greater detail. Conventional decode logic is provided atreference numeral 1410. All cards in computer 350 contain the same sortof decode logic. An output port 1412 is connected to failsafe logic1414. Failsafe logic 1414 is used to prevent mutually exclusiveconditions, such as travelling forward and reverse at the same time.

Another output port 1416 has the same logic as output port 1412. Aninput port 1418 is connected to debounce circuitry 1420. In general, allinput ports described herein are similar to input port 1418 and alloutput ports are similar to output port 1412. Output port 1422,connected to digital/analog converters 1423, results in changing thespeed or horn amplitude shown at reference numeral 1424.

As used herein, the designation PPI refers to parallel ports and arenumbered consecutively from PPI 1 through PPI 5. The proper operation ofsuch parallel ports is monitored by corresponding selectable items inthe aforementioned menus.

Referring now to FIG. 15, there is shown the Butterworth guidancecontrol card 812 (FIG. 8) in greater detail. A microprocessor 1510 suchas is manufactured by Motorola corporation as Model no. 68705 containsfirmware for guidance control algorithms. In general, guidance controlalgorithms control movement of AGVs despite unequal loading, anomaliesthat occur during turns, and other maneuvers and the like.

Microprocessor 1510 communicates with the AGV computer, not shown, bymeans of standard decode logic 1511. Connected to microprocessor 1510 isa parallel port 1512 which forms the gateway of communications betweenmicroprocessor 1510 and AGV computer, not shown. Connected tomicroprocessor 1510 by means of PPI 1512 are sensors from the guidancesystem 1514, such as position sensors, phase, center, forward andreverse for front and rear wheels, and steering. Also connected to PPI1512 is a temperature circuit 1516 to indicate the temperature of thevehicle.

Referring now to FIG. 16, there is shown the digital card 846 (FIG. 8)in greater detail. Level shift 1610 debounces signals that are inputthereto and translates all signals to proper voltage levels between 5volts and ground. The self test circuitry 1612 is used on power up totest all operating systems in the vehicle. A tri-state buffer 1614connected to self test unit 1612 and input signals at level shift 1610allows an operator to detect the status of any diagnostics bits that areinput to level shift 1610. In other words, tri-state buffer 1614provides the state of all of the input levels in a logic sense.

Thus, any of the functions that are input to level shift 1610 (e.g.,proximity sensor or deadman/enter), are continually monitored andprovided at tri-state buffer 1614. When the signal is active, it isdesignated as a binary 1 and when inactive it is designated binary valueis 0. Since the aforementioned process is a real time operation, anymonitored anomaly results in the tri-state buffer immediately shiftingfor the associated bit. When the anomaly is removed, the tri-statebuffer immediately resets to a nominal value.

A priority interrupt chip 1616 is connected to tri-state buffer 1614 forinterrupting system operation upon sensing an anomaly. A serial port1618 is used to interface to guidance sensor 844 (FIG. 8). Twoadditional serial ports 1618a and 1618b are unused in the presentembodiment.

Referring now to FIG. 17, there is shown the nonvolatile memory card 850(FIG. 8) in greater detail. A communications bus interface 1710 isprovided to pass information to a precision distance shaft and encoder1712 which is operatively connected to the axle of side wheels of thevehicle 132. Precision distance in encoder 1712 allows for precisedistance measurement based on rotation of the axle. While coarsemeasurements are made from the front and rear wheels, for very precisemeasurement within fractions of an inch, the precision shaft and encoder1712 is used. Shaft encoder 1712 allows the unit to act in a rotate andadvance mode wherein each of the two side wheels is monitoredindependently. The effect is to have the AGV positioned very accuratelydespite vehicle turns.

Also connected to communications bus interface 1710 is an EPROM(reference numeral 728 in FIG. 7) such as is

provided by Intel Corp. as Model no. 27C512, having 64K bytes of memory.EPROM 1714 stores operations program instructions. EPROM 1714 containsalgorithms and instructions to perform the following functions:

a) all diagnostics

b) map of floor

c) pathfinding

d) traffic control

e) communications

f) speed control

g) safety functions

h) built in self test

i) power on self test

The aforementioned functions are programmable and, of course, aredependent upon the environment in which the AGV system is to operate.For example, the map of the floor must change with each facility.

Accordingly, an operator can change AGV critical instructions merely byexchanging one EPROM 1714 for another, suitably programmed EPROM. Inthis way, the AGV can be customized easily for greatest flexibilitywithout the necessity of changing hardware.

Also connected to communications bus interface 1710 is an 8K nonvolatileRAM 1716. RAM 1716 is used to maintain data in the event of powerinterruption. Such data may consist of previous transactions, in whichcase the data stored in RAM 1716 can be used much like a flightrecorder, and can be analyzed to determine what caused malfunctions orpower interruptions themselves. The stored data can be used when poweris resupplied to the system.

Also connected to communications bus interface 1710 is a display buffer1718 for driving the electroluminescent display H (FIG. 5a).

Referring now to FIG. 18, there is shown the traffic manager whichresides in control box 119 (FIG. 1) and which contains software such asthat described hereinabove with respect to FIG. 12. Decode logic isshown generally at reference numeral 1810, and is similar to the decodelogic used on other cards hereinabove mentioned. When a computer such asa PC/XT is driving the system, decode logic 1810 is used to interfacesuch computer to the rest of the board.

Microprocessor or CPU 1812, manufactured by Motorola Corp. as Model no.68HC11 is provided to control traffic. Connected to CPU 1812 is data1814 for allowing a PC/XT, not shown, to communicate therewith.

Serial communication ports 1816 are connected to microprocessor 1812.

Seventeen traffic output signals are provided at connector 1818 whichallow data from microprocessor 1812 to enable an external card, notshown, to excite a receiver loop disposed under the surface of thefloor.

Similarly, a twelve-signal traffic input connector 1820 is used toreceive a signal from the transmit coil in the AGV. The signal isdemodulated by circuitry shown generally at reference numeral 1822.Thus, a tone that is received at connector 1820 is converted to a logiclevel. If traffic is present, a logical 1 is transferred tomicroprocessor 1812.

Since other modifications and changes varied to fit particular operatingrequirements and environments will be apparent to those skilled in theart, the invention is not considered limited to the example chosen forpurposes of disclosure, and covers all changes and modifications whichdo not constitute departures from the true spirit and scope of thisinvention.

What is claimed is:
 1. An automatic guided vehicle (AGV) fortransporting material between at least two pickup and delivery standswithin a warehouse-type facility, said automatic guided vehicle (AGV)being part of a hierarchial traffic control and routing systemcomprising:a) a chassis adapted to carry material; b) informationprocessing means carried by, and integrally disposed upon said chassisfor controlling and monitoring AGV operation upon said chassis includingthe routing thereof; and c) an interactive display including a CRTscreen operatively connected to said information processing means andsupported by said chassis, said CRT screen of said interactive displayhaving means for simultaneously displaying both diagnostic and routinginformation thereon, said diagnostic information being menu controllablevia said information processing means, and said display and informationprocessing means being operative to display said diagnostic informationin analog, digital and graphical format.
 2. The AGV in accordance withclaim 1 further comprising:d) diagnostic means for interrogatinginternal conditions of the AGV, and wherein disagnostic informationcomprises alphanumeric characters.
 3. The AGV in accordance with claim 2wherein said diagnostic information comprises graphic representation. 4.The AGV in accordance with claim 2 wherein said diagnostic informationis displayed in menu driven form.
 5. The AGV in accordance with claim 4further comprising:d) alarm signal generating means operativelyconnected to said information processing means for indicating acondition of said AGV.
 6. The AGV in accordance with claim 5 whereinsaid alarm signal generating means generates an audible signal.
 7. TheAGV in accordance with claim 6 wherein said alarm signal generatingmeans comprises a tone generator.
 8. The AGV in accordance with claim 6wherein said alarm signal generating means comprises a speechsynthesizer.
 9. The AGV in accordance with claim 5 further comprising:e)a manual controller for interrogating said information processing means.10. The AGV in accordance with claim 9 wherein said alarm signalgenerating means comprises a speech synthesizer.
 11. The AGV inaccordance with claim 5 wherein said alarm signal generating meanscomprises a speech synthesizer.
 12. The AGV in accordance with claim 5wherein said diagnostic information comprises information indicative ofbattery voltage.
 13. The AGV in accordance with claim 5 wherein saiddiagnostic information comprises information indicative of objects inthe path of said AGV.
 14. The AGV in accordance with claim 5 whereinsaid diagnostic information comprises information indicative of objectsin physical contact with said AGV.
 15. The AGV in accordance with claim5 further comprising:d) a modem operatively connected to saidinformation processing means for facilitating communication between saidinformation processing means and a remote device.
 16. The AGV inaccordance with claim 5 wherein said diagnostic information comprisesinformation indicative of status of an AGV subsystem.
 17. The AGV inaccordance with claim 5 wherein said diagnostic information comprisesinformation indicative of steering assembly operation.
 18. The AGV inaccordance with claim 5 wherein said diagnostic information comprisesinformation indicative of guidance control system operation.
 19. The AGVin accordance with claim 2 wherein said information processing meanscomprises a computer having a central processing unit.
 20. The AGV inaccordance with claim 2 further comprising:d) a manual controller forinterrogating said information processing means.
 21. The AGV inaccordance with claim 20 wherein said alarm signal generating meanscomprises a speech synthesizer.
 22. The AGV in accordance with claim 1further comprising:d) a modem operatively connected to said informationprocessing means for facilitating communication between said informationprocessing means and a remote device.
 23. An interactive diagnosticsubsystem for use upon a chassis of an automatic guided vehicle (AGV)being guided through a warehouse according to a facility floor plan andwhich is part of a hierarchial routing and traffic control system,comprising:a) information processing means for monitoring a plurality ofAGV operating conditions; b) an interactive display means including aCRT screen operatively connected to said information processing meansfor displaying information in analog, digital and graphical format; andc) means operatively connected to said information processing means andto said display means for updating information displayed thereonresponsive to changes in one of said plurality of AGV operatingconditions.
 24. The interactive diagnostic subsystem in accordance withclaim 23 wherein operational information comprises alphanumericcharacters.
 25. The interactive diagnostic subsystem in accordance withclaim 24 further comprising:d) alarm signal generating means operativelyconnected to said information processing means for indicating one ofsaid plurality of AGV conditions.
 26. The interactive diagnosticsubsystem in accordance with claim 24 further comprising:d)interrogating means operatively connected to said information processingmeans for generating responses on said display means for simultaneousdisplay of at least two of said plurality of AGV operating conditions.27. The interactive diagnostic subsystem in accordance with claim 24wherein said diagnostic information comprises information indicative ofbattery voltage.
 28. The interactive diagnostic subsystem in accordancewith claim 24 wherein said diagnostic information comprises informationindicative of objects in the path of said AGV.
 29. The interactivediagnostic subsystem in accordance with claim 24 wherein said diagnosticinformation comprises information indicative of objects in physicalcontact with said AGV.
 30. The interactive diagnostic subsystem inaccordance with claim 24 wherein said diagnostic information comprisesinformation indicative of status of an AGV subsystem.
 31. Theinteractive diagnostic subsystem in accordance with claim 24 whereinsaid diagnostic information comprises information indicative of steeringassembly operation.
 32. The interactive diagnostic subsystem inaccordance with claim 24 wherein said diagnostic information comprisesinformation indicative of guidance control system operation.